@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --color-primary: #FFFFFF;
    --color-on-primary: #0F172A;
    --color-secondary: #93C5FD;
    --color-accent: #3B82F6;
    --color-accent-hover: #2563EB;
    --color-accent-light: #DBEAFE;
    --color-accent-lighter: #EFF6FF;
    --color-background: #F1F5F9;
    --color-foreground: #0F172A;
    --color-muted: #64748B;
    --color-border: #E2E8F0;
    --color-surface: #FFFFFF;
    --color-destructive: #EF4444;
    --color-success: #10B981;
    --color-ring: rgba(59, 130, 246, 0.3);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--color-background);
    color: var(--color-foreground);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.6;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
}

.card {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: box-shadow var(--transition-normal), transform var(--transition-normal);
    overflow: hidden;
    background: var(--color-surface);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0 !important;
    border-bottom: 1px solid var(--color-border);
    padding: 1.25rem 1.5rem;
    background: var(--color-surface);
    font-weight: 600;
    color: var(--color-foreground);
}

.btn {
    border-radius: var(--radius-sm);
    padding: 0.625rem 1.25rem;
    font-weight: 500;
    font-size: 0.875rem;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    line-height: 1.5;
    letter-spacing: 0.01em;
}

.btn:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.btn-primary {
    background-color: var(--color-accent);
    color: #FFFFFF;
    box-shadow: 0 1px 3px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: 0 1px 3px rgba(59, 130, 246, 0.3);
}

.btn-outline-primary {
    background-color: transparent;
    color: var(--color-accent);
    border: 1.5px solid var(--color-accent);
}

.btn-outline-primary:hover {
    background-color: var(--color-accent);
    color: #FFFFFF;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
}

.btn-outline-success {
    background-color: transparent;
    color: var(--color-success);
    border: 1.5px solid var(--color-success);
}

.btn-outline-success:hover {
    background-color: var(--color-success);
    color: #FFFFFF;
    transform: translateY(-1px);
}

.btn-success {
    background-color: var(--color-success);
    color: #FFFFFF;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
}

.form-control {
    border-radius: var(--radius-sm);
    border: 1.5px solid var(--color-border);
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    transition: all var(--transition-normal);
    background: var(--color-surface);
    color: var(--color-foreground);
    font-family: inherit;
}

.form-control:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-ring);
    outline: none;
}

.form-control::placeholder {
    color: var(--color-muted);
    opacity: 0.7;
}

.form-control.is-invalid {
    border-color: var(--color-destructive);
}

.form-label {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--color-foreground);
    margin-bottom: 0.375rem;
}

.navbar {
    box-shadow: var(--shadow-sm);
    border-bottom: 1px solid var(--color-border);
}

.navbar-brand {
    font-weight: 600;
    font-size: 1.125rem;
    letter-spacing: -0.01em;
}

.alert {
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    font-size: 0.875rem;
}

.alert-success {
    background-color: #ECFDF5;
    border-color: #A7F3D0;
    color: #065F46;
}

.alert-danger {
    background-color: #FEF2F2;
    border-color: #FECACA;
    color: #991B1B;
}

.spinner-border {
    width: 2.5rem;
    height: 2.5rem;
    border-width: 3px;
}

#subtitleContent {
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.875rem;
    line-height: 1.7;
    background-color: var(--color-accent-lighter);
    border: 1.5px solid var(--color-accent-light);
    resize: vertical;
    border-radius: var(--radius-sm);
}

#subtitleContent:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-ring);
}

#charCount {
    font-weight: 600;
    color: var(--color-accent);
    font-variant-numeric: tabular-nums;
}

#videoInfo {
    background-color: var(--color-accent-lighter);
    padding: 0.875rem 1rem;
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--color-accent);
    font-size: 0.875rem;
}

.info-section {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: 1.75rem;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.4s ease-out forwards;
}

.slide-up {
    animation: slideUp 0.5s ease-out forwards;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.03);
    }
}

.pulse {
    animation: pulse 0.3s ease-in-out;
}

#subtitleContent::-webkit-scrollbar {
    width: 6px;
}

#subtitleContent::-webkit-scrollbar-track {
    background: transparent;
}

#subtitleContent::-webkit-scrollbar-thumb {
    background: var(--color-secondary);
    border-radius: 3px;
}

#subtitleContent::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}

.status-indicator {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    margin-right: 8px;
}

.status-success {
    background-color: var(--color-success);
}

.status-error {
    background-color: var(--color-destructive);
}

.status-loading {
    background-color: #F59E0B;
    animation: pulse 1s infinite;
}

.tooltip {
    font-size: 0.8125rem;
}

@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .card {
        margin: 8px 0;
    }

    .btn {
        padding: 0.5rem 1rem;
    }

    .navbar-brand {
        font-size: 1rem;
    }

    .form-control {
        padding: 0.625rem 0.875rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}